1. Field
Apparatuses and methods consistent with exemplary embodiments relate to three-dimensional (3D) glasses, a method for driving 3D glasses and a system for providing a 3D image, and more particularly, to 3D glasses for viewing a 3D image in which left eye image and right eye image are displayed alternately, a method for driving 3D glasses and a system for providing a 3D image.
2. Description of the Related Art
3D stereoscopic image technology is applicable to various fields such as information communication, broadcasting, medicine, education & training, military, games, animation, virtual reality, computer-aided design (CAD), and industrial technology, and is regarded as a core base technology for the next generation 3D stereoscopic multimedia information communication, which is utilized in all the aforementioned fields.
Generally, a stereoscopic sense that a person perceives occurs from a complex effect due to a degree of change of thickness of the person's eye lens according to the location of an object being perceived, a difference in the angle of the object as perceived by both eyes, differences in location and shape of the object as perceived by both eyes, a disparity due to a movement of the object, and various other psychological and memory effects.
In particular, binocular disparity, caused by an approximate 6˜7 cm lateral distance between the person's left eye and right eye, can be regarded as the main cause of the stereoscopic sense. Due to binocular disparity, the person perceives the object at different angles, which makes the left eye and the right eye receive different images, and when these two images are transmitted to the person's brain through the retinas, the brain can perceive the original 3D stereoscopic image by combining the two pieces of information exactly.
There are two types of stereoscopic image display apparatuses: glasses-type apparatuses which use special glasses, and nonglasses-type apparatuses which do not use such special glasses. A glasses-type apparatus may use a color filtering method which separates the images received by the left eye and the right eye by using color filters of complementary colors, a polarized filtering method which separates the images using a light-shading effect caused by a combination of polarized light elements meeting at right angles, or a shutter glasses method which enables a person to perceive a stereoscopic sense by alternately blocking the left eye and the right eye in response to a sync signal coordinated with the projection of a left eye image and a right eye image on a screen.
In a related art shutter glasses method, a sync signal is employed to synchronize left and right eye shutters with the display of a left image and a right image. However, the left eye image and the right eye image are not exactly synchronized with the glasses in terms of the timing of opening or closing the shutters and the time during which the shutters are opened or closed and thus, cross-talk and degradation of resolution and the stereoscopic sense may occur.
In addition, a sync signal frequently causes errors or cross-talk due to external light, external electromagnetic waves, or noises in a display apparatus itself.
Furthermore, operating a sync signal requires a circuit and an apparatus configuration unit. Moreover, if a plurality of viewers are out of the range of a sync signal, 3D effect may not be achieved in many occasions.
Accordingly, a method for allowing a user to watch a 3D image without a sync signal is required.